Molecular modifications of dermal and epidermal biomarkers following UVA exposures on reconstructed full-thickness human skin

Abstract

Ultraviolet A (UVA) radiation adversely affects skin health and appearance via multiple molecular pathways. Biologically relevant UVA damage are classified as short-term effects (e.g. formation of reactive oxygen species [ROS], inflammation, photo-oxidation, DNA damage, immunosuppression, photoallergy and cell-mediated contact hypersensitivity) or long-term effects (elastosis, photoageing and photocarcinogenesis). Single and chronic experimental exposure to UVA are limited in humans by ethical concerns, and furthermore it is impossible to quantify long-term endpoints such as photoageing over the life-span of a human volunteer. The aim of the present study was to investigate the biological relevance of the Phenion FT skin model for use in photobiological studies. Biological responses to acute and repeated UVA exposures were investigated by monitoring the kinetics of gene expression during the post-irradiation period. By using a dynamic approach, we were able to define early and stable markers of UVA-induced effects that could be predictive of UVA damage in vivo. The transcriptomic approach applied to 3D human tissues appears to be an encouraging method for gaining a deeper understanding of the UVA effects on skin and for studying the dermal response with non-invasive techniques.